A UK-flag multipurpose ship left the scene of a fatal collision in Swedish waters in the early hours of Monday, shipowner Scotline has acknowledged.

One person remains missing after the collision of Scotline's 4,800-dwt Scot Carrier (built 2018) and the 492-dwt Danish cargo ship Karin Hoj (built 1997). One body, still unidentified, was found in the capsized Karin Hoj, which has been towed to Ystad harbour.

TradeWinds previously reported that two Scotlines crew members were detained on suspicion of offences including manslaughter, gross negligence and drunkenness at sea, amid Swedish media reports that the incident was a hit-and-run.

In a statement, UK-based Scotline Marine Holdings has acknowledged that Scot Carrier left the scene after the accident and reversed course to help search for two seafarers.

"It is understood that the time between the incident and the Scot Carrier altering course to the location of the incident was under 25 minutes," wrote a company representative in an updated statement to TradeWinds.

He said that after the collision, the Karin Hoj's emergency position-indicating radio beacon (EPIRB) of the [Karin Hoj] was activated and then Swedish authorities contacted the Scot Carrier.

"The second officer, who was on the bridge at the time, requested the master to come to the bridge of the Scot Carrier where he reported contact with the Swedish coastguard," the representative said.

"Once all crew members had been accounted for and an initial damage assessment completed, the Scot Carrier returned to the location of the incident and launched a rescue boat to participate in the search and rescue operation."

Some accounts of the incident have characterised Karin Hoj as a barge, but the Danish shipowner's website shows that it is a self-propelled vessel.

It was not immediately possible to reach Swedish authorities for an update of the search for the remaining victim but Swedish media reports late today indicated no second body has been found.

Scotline previously acknowledged that two of its crewmen had been detained after drug and alcohol testing.

Swedish prosecutors have characterised the two men detained as a UK citizen born in 1991 and a Croatian citizen born in 1965.

In television and online media reports, Swedish prosecutor Tomas Olvmyr has said the UK citizen was on watch at the time of the incident.

The watchkeeper is under investigation for aggravated drunkenness at sea, aggravated negligence in maritime traffic, and aggravated causing of the death of another, which is an offence corresponding to manslaughter.

The Croatian seafarer is under investigation for aggravated drunkenness at sea.